To boldly go to a commercial space age

If the US wishes to continue its human space exploration endeavours in this century it must find a new, more sustainable strategy and commercial providers hold the key to this. The question is not "if" but "when" they should start to rely upon private industry to do some of the things that their national space agency used to. Getting the timing wrong would decimate Nasa's army of aerospace engineers, leave their astronauts without a ride and irreversibly damage their space exploration capabilities.